The invention relates to the technical field of medical diagnosis auxiliary equipment, in particular to a lamp box used for medical image observation. The lamp box comprises a box body and an image amplification mechanism connected with the box body, the image amplification mechanism comprises a plurality of magnifying lenses; one side edge of the box body is connected with a fixed seat; a connecting shaft is arranged on the fixed seat; one end of the rotating rod is rotationally connected with the connecting shaft and the other end is connected with the magnifying lenses, a rotary fixing mechanism is arranged between the opposite side faces of the rotary rod and the connecting shaft. A structure that the rotating rod rotates relative to the connecting shaft and is fixed and clamped by therotary fixing mechanism is formed; the rotating rod is telescopic, that is, the rotating rod can be telescopic and rotated to drive the magnifying lenses to move to a proper position, the rotating rod can be kept at a fixed angle and does not rotate, meanwhile, the rotating rod can be conveniently retracted to the side edge of the box body when not used, and normal watching of doctors is not affected.